Pollution and climate change threaten fish in Ecuador’s Amazon region

RIO DE JANEIRO, BRAZIL – Pollution and climate change, among other factors, threaten the wide variety of fish that inhabit Ecuador’s rivers, especially in the Amazon region, where this resource is vital for the subsistence of many native peoples.

This was explained by Jonathan Valdiviezo, an ichthyologist from the National Biodiversity Institute (Inabio), one of the authors of a study on the threats to freshwater fish in Ecuador due to factors such as deforestation, mining, oil extraction, overfishing, and the introduction of foreign species, among others.

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The research, he said, began with the objective of getting to know the different species of freshwater fish that inhabit the country and, above all, to try to answer the question: “What is happening to Ecuador’s rivers”?

According to Valdiviezo, there are an estimated 900 species of fish in the country, 720 of them in the Ecuadorian Amazon, about 120 in the coastal area, and a small percentage in the mountainous area of the Andes.

The study, he added, seeks to raise awareness of the importance of preserving “freshwater” resources, which are also fundamental for conserving different ecosystems.

The research, published in the journal Fish Biology, warns that there is no “sustainable management of the resource” in the country, which is aggravated by the high contamination of rivers.

River and lake pollution has reached such a level in Ecuador that “high levels of heavy metals” have even been found in fish from the Amazon region, it added.

The deterioration of the “freshwater” resource, Valdiviezo explained, also has repercussions on human beings, especially among the native populations that inhabit the Amazon and whose main source of protein is fish.

In addition, these species “fulfill essential functions in the conservation of aquatic ecosystems” since there are fish specialized in cleaning rivers and eliminating waste.

According to Valdivieso, piranhas, for example, play a “fundamental role”, as they are like “river scavengers”, responsible for keeping the Amazonian tributaries clean.

There are also species “that feed only on microorganisms or only on algae, and omnivores have also appeared,” some of which are important in seed dispersal and the regulation of insect populations in certain areas.

According to Valdviezo, the study suggests a series of recommendations that involve creating a national freshwater fish tracking and monitoring system and the development of regulations to prevent the disappearance of species.

For example, fishing bans should be applied to certain species. Above all, regulations should be created to prevent other activities, such as mining, from contaminating the country’s water resources.

Valdiviezo cited Colombia as an example, where the country’s scientific community has achieved “sustainable management in some parts of its Amazonian rivers”.

The Inabío study, which counts on the collaboration of national and foreign scientists, aims to be “a first step” in the elaboration of indispensable information that will allow decision-makers, especially the authorities, to apply norms for the sustainable management of the “freshwater” resource.

“Freshwater fish are an important component of the biological and cultural legacy of the Ecuadorian people. Conserving them for future generations is vital,” reads the study’s main conclusion.